During the PE, odidiscovered that one or both of the tailgate support cables can break due to the effects of metal fatigue at the point where the cable flexes when the lift gate is opened and closed. Concurrently, the strength of the cable degrades over time due to corrosion of the wire strands in the support cables.when the vehicle is stationary and cargo is being loaded or unloaded, the tailgate can tip downward displacing cargo and/or people to the ground without warning.ODI is also aware of one total separation of the tailgate from the vehicle.owners cannot easily detect whether the support cabes are damaged or corroded because they are covered by a protective sheath.ODI is upgrading this preliminary evaluation for further appropriate action.model year 2003 vehicles will be added to the investigation.further, we will incude additional vehicles, those being the Avalanche and Cadillac ext, model years 2002-2003, and the Sierra, model years 1999-2003.